Stimulus factors in the isolation-induced aggression of Bobwhite quail and Khaki Campbell ducklings

Components of aggression in chickens and conceptualizations of aggression in general.

“…Although the term peck order is widely used by both scientist and layman, there is surprisingly little agreement as to just what sort of pecking or other form of behavior might constitute an aggressive response in young precocial birds. Some investigators have regarded any intersubject pecking as aggressive (ducklings and quail chicks: Eiserer, Emerling, Scardina, & Hoffman, 1976); others have restricted attention to pecks that cause the withdrawal of the opponent (ducklings: Hoffman, Boskoff, Eiserer, & Klein, 1975), whereas still others have concentrated on the locus of pecking (chicks: Rajecki, Ivins, & Rein, 1976).…”

The effects of tactile stimulation on imprinting in ducklings after the sensitive period

“…In the context of intraspecific aggression, for example, tactile stimulation from a conspecific-even without concurrent visual stimulation-is. sufficient to largely reduce the subsequent occurrence of aggressive behavior in both quail and ducklings (Eiserer, Emerling, Scardina, & Hoffman, 1976). In the context of imprinting, Collias (1952) found that contact with a human hand can reduce distress calling in newly hatched chicks; Thompson and Dubanoski (1964) reported that physical handling enhanced subsequent imprinting in 5-h-old (but not in 9-h-old) chicks; Maier and Maier (1970, p. 202) suggested that contact is important in maintaining the following response of older chicks; and Clements and Lien (1975) found that contact facilitated initiation and maintenance of following behavior in newly hatched quail.…”